1. Technical Field
The present invention relates to liners such as trayliners and shelf-liners for use in a sterilization process and, more particularly, to an absorbent liner for cushioning surgical instruments and sterilization packs and providing an advantageous moisture absorption functionality during and after completion of a sterilization process. In a preferred embodiment of the present invention, an absorbent, foam plastic absorbent liner is disclosed for cushioning surgical instruments and sterilization packs and providing an advantageous moisture absorption functionality during and after sterilization procedures that utilize steam and/or ethylene oxide gas as a sterilization agent.
2. Background of the Related Art
As is well known, surgical instruments used in the healthcare industry must be sterilized before and after each use. Sterilization, of course, frees instruments from microorganism contamination, to prevent infections and the spread of diseases among patients. All medical procedures rely upon a stringent program of sterilization.
The medical device industry has addressed the sterilization requirements in the surgical field by offering two general types of surgical instruments: reusable instruments and single use, or disposable instruments. Reusable instruments are typically composed of stainless steel and are typically sterilized before their initial use and then cleaned and resterilized prior to each subsequent use thereof. Single use or disposable instruments, on the other hand, are often fabricated primarily from plastic materials, thereby reducing costs associated with manufacture, and are discarded after use in a single procedure.
With respect to reusable surgical instruments, e.g., forceps, graspers, dissectors, probes, hemostats, scissors and the like, historically sterilization and resterilization have been accomplished using two primary sterilization modalities: steam sterilization and ethylene oxide sterilization. Of the two primary sterilization modalities, steam sterilization has been the overwhelmingly dominant method of sterilization in the surgical instrument field. In a broad sense, the sterilization process generally involves placing instruments to be sterilized in a tray, wrapping the instruments and the tray with a sterilization wrap, and placing the wrapped tray and instruments in a sterilization chamber where the instruments are exposed to the sterilization medium of either steam or ethylene oxide. Preferably, the instruments are placed in a tray and wrapped before initiating exposure to the sterilization medium. Wrapping the tray generally contributes to providing a level of protection to the surgical instruments, e.g., during post-sterilization storage and handling prior to actual use, and to maintaining the instruments in a dry, sterile condition. Typically, sterilization trays are wrapped with a sterilization wrap, e.g., paper. Other instruments to be sterilized include basins. Basins are separated by cotton towels or other absorbent materials and then wrapped in sterilization wrap prior to sterilization.
One long and continuing problem encountered with steam and/or ethylene oxide sterilization, however, is the presence of moisture that remains on the implements such as on sterilized instruments, i.e., within the sterile wrap, at the conclusion of the sterilization process. This residual moisture can range from slight levels of dampness to visible droplets on the surface of surgical instruments. Such residual moisture is both undesirable and is unacceptable because such moisture could permit migration of surface microorganisms, thereby penetrating the wrapped tray or basin and rendering its contents contaminated.
A wrapped tray or basin with residual moisture has been termed a “wet pack,” i.e., a wrapped tray containing surgical instruments having surface moisture on the inside and/or outside of the wrapped tray, e.g., during and after the sterilization process. In one of its marketing publications, Getinge/Castle, Inc. of Rochester, N.Y., a major manufacturer of sterilizers, refers to the “wet pack” problem as “an age old predicament.” Wet pack problems may be caused and/or exacerbated by, e.g., the use of new sterilizers, boiler or plumbing changes or even ambient humidity variations due to air conditioning, etc.
Another problem arises when the wrapped trays and basins are loaded on sterilization carts having multiple shelves and rails and which are then wheeled into a sterilizer where the wrapped trays are sterilized along with the cart. In such a case, condensation may drip from a shelf or a rail onto the wrapped tray causing a wet pack. Also, the wrapped tray or basin may become stained during sterilization or even torn during loading or removal from a sterilization cart because of the condition of the sterilization cart. That is because during repeated use, the sterilization carts may begin to oxidize and degrade exposing sharp edges.
In some cases, shelves of sterilization carts may be laboriously wrapped with absorbent wrappers or thermal blankets that then must be adhered to the shelves. In a further step, the edges of the absorbent wrappers or thermal blankets must also be bound to prevent fraying and shedding of the wrappers or blankets and subsequent passage thereof into the sterilization medium. Since the absorbent wrappers and thermal blankets require a large amount of labor to replace, the sterilization carts generally undergo an excessively high number of sterilization cycles in the sterilizer before they are replaced. This allows for the buildup of undesirable materials and microorganisms within the absorbent wrappers and thermal blankets.
What is needed, therefore, is a more effective means than, e.g., a paper or cotton product for preventing wet packs, degradation of sterilization carts, the labor intensive replacement of shelf-liners and the resulting potential for contamination of sterilized surgical instruments.